FFmpeg: libavcodec/alsdec.c Source File

00001 /*
00002  * MPEG-4 ALS decoder
00003  * Copyright (c) 2009 Thilo Borgmann <thilo.borgmann _at_ googlemail.com>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00029 //#define DEBUG
00030 
00031 
00032 #include "avcodec.h"
00033 #include "get_bits.h"
00034 #include "unary.h"
00035 #include "mpeg4audio.h"
00036 #include "bytestream.h"
00037 #include "bgmc.h"
00038 
00039 #include <stdint.h>
00040 
00045 static const int8_t parcor_rice_table[3][20][2] = {
00046     { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},
00047       { 12, 3}, { -7, 3}, {  9, 3}, { -5, 3}, {  6, 3},
00048       { -4, 3}, {  3, 3}, { -3, 2}, {  3, 2}, { -2, 2},
00049       {  3, 2}, { -1, 2}, {  2, 2}, { -1, 2}, {  2, 2} },
00050     { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},
00051       { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},
00052       {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},
00053       {  7, 3}, { -4, 4}, {  3, 3}, { -1, 3}, {  1, 3} },
00054     { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},
00055       { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},
00056       {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},
00057       {  3, 3}, {  0, 3}, { -1, 3}, {  2, 3}, { -1, 2} }
00058 };
00059 
00060 
00066 static const int16_t parcor_scaled_values[] = {
00067     -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,
00068     -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,
00069     -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,
00070     -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,
00071     -1013728 / 32, -1009376 / 32, -1004768 / 32,  -999904 / 32,
00072      -994784 / 32,  -989408 / 32,  -983776 / 32,  -977888 / 32,
00073      -971744 / 32,  -965344 / 32,  -958688 / 32,  -951776 / 32,
00074      -944608 / 32,  -937184 / 32,  -929504 / 32,  -921568 / 32,
00075      -913376 / 32,  -904928 / 32,  -896224 / 32,  -887264 / 32,
00076      -878048 / 32,  -868576 / 32,  -858848 / 32,  -848864 / 32,
00077      -838624 / 32,  -828128 / 32,  -817376 / 32,  -806368 / 32,
00078      -795104 / 32,  -783584 / 32,  -771808 / 32,  -759776 / 32,
00079      -747488 / 32,  -734944 / 32,  -722144 / 32,  -709088 / 32,
00080      -695776 / 32,  -682208 / 32,  -668384 / 32,  -654304 / 32,
00081      -639968 / 32,  -625376 / 32,  -610528 / 32,  -595424 / 32,
00082      -580064 / 32,  -564448 / 32,  -548576 / 32,  -532448 / 32,
00083      -516064 / 32,  -499424 / 32,  -482528 / 32,  -465376 / 32,
00084      -447968 / 32,  -430304 / 32,  -412384 / 32,  -394208 / 32,
00085      -375776 / 32,  -357088 / 32,  -338144 / 32,  -318944 / 32,
00086      -299488 / 32,  -279776 / 32,  -259808 / 32,  -239584 / 32,
00087      -219104 / 32,  -198368 / 32,  -177376 / 32,  -156128 / 32,
00088      -134624 / 32,  -112864 / 32,   -90848 / 32,   -68576 / 32,
00089       -46048 / 32,   -23264 / 32,     -224 / 32,    23072 / 32,
00090        46624 / 32,    70432 / 32,    94496 / 32,   118816 / 32,
00091       143392 / 32,   168224 / 32,   193312 / 32,   218656 / 32,
00092       244256 / 32,   270112 / 32,   296224 / 32,   322592 / 32,
00093       349216 / 32,   376096 / 32,   403232 / 32,   430624 / 32,
00094       458272 / 32,   486176 / 32,   514336 / 32,   542752 / 32,
00095       571424 / 32,   600352 / 32,   629536 / 32,   658976 / 32,
00096       688672 / 32,   718624 / 32,   748832 / 32,   779296 / 32,
00097       810016 / 32,   840992 / 32,   872224 / 32,   903712 / 32,
00098       935456 / 32,   967456 / 32,   999712 / 32,  1032224 / 32
00099 };
00100 
00101 
00105 static const uint8_t ltp_gain_values [4][4] = {
00106     { 0,  8, 16,  24},
00107     {32, 40, 48,  56},
00108     {64, 70, 76,  82},
00109     {88, 92, 96, 100}
00110 };
00111 
00112 
00116 static const int16_t mcc_weightings[] = {
00117     204,  192,  179,  166,  153,  140,  128,  115,
00118     102,   89,   76,   64,   51,   38,   25,   12,
00119       0,  -12,  -25,  -38,  -51,  -64,  -76,  -89,
00120    -102, -115, -128, -140, -153, -166, -179, -192
00121 };
00122 
00123 
00126 static const uint8_t tail_code[16][6] = {
00127     { 74, 44, 25, 13,  7, 3},
00128     { 68, 42, 24, 13,  7, 3},
00129     { 58, 39, 23, 13,  7, 3},
00130     {126, 70, 37, 19, 10, 5},
00131     {132, 70, 37, 20, 10, 5},
00132     {124, 70, 38, 20, 10, 5},
00133     {120, 69, 37, 20, 11, 5},
00134     {116, 67, 37, 20, 11, 5},
00135     {108, 66, 36, 20, 10, 5},
00136     {102, 62, 36, 20, 10, 5},
00137     { 88, 58, 34, 19, 10, 5},
00138     {162, 89, 49, 25, 13, 7},
00139     {156, 87, 49, 26, 14, 7},
00140     {150, 86, 47, 26, 14, 7},
00141     {142, 84, 47, 26, 14, 7},
00142     {131, 79, 46, 26, 14, 7}
00143 };
00144 
00145 
00146 enum RA_Flag {
00147     RA_FLAG_NONE,
00148     RA_FLAG_FRAMES,
00149     RA_FLAG_HEADER
00150 };
00151 
00152 
00153 typedef struct {
00154     uint32_t samples;         
00155     int resolution;           
00156     int floating;             
00157     int frame_length;         
00158     int ra_distance;          
00159     enum RA_Flag ra_flag;     
00160     int adapt_order;          
00161     int coef_table;           
00162     int long_term_prediction; 
00163     int max_order;            
00164     int block_switching;      
00165     int bgmc;                 
00166     int sb_part;              
00167     int joint_stereo;         
00168     int mc_coding;            
00169     int chan_config;          
00170     int chan_sort;            
00171     int rlslms;               
00172     int chan_config_info;     
00173     int *chan_pos;            
00174 } ALSSpecificConfig;
00175 
00176 
00177 typedef struct {
00178     int stop_flag;
00179     int master_channel;
00180     int time_diff_flag;
00181     int time_diff_sign;
00182     int time_diff_index;
00183     int weighting[6];
00184 } ALSChannelData;
00185 
00186 
00187 typedef struct {
00188     AVCodecContext *avctx;
00189     ALSSpecificConfig sconf;
00190     GetBitContext gb;
00191     unsigned int cur_frame_length;  
00192     unsigned int frame_id;          
00193     unsigned int js_switch;         
00194     unsigned int num_blocks;        
00195     unsigned int s_max;             
00196     uint8_t *bgmc_lut;              
00197     unsigned int *bgmc_lut_status;  
00198     int ltp_lag_length;             
00199     int *use_ltp;                   
00200     int *ltp_lag;                   
00201     int **ltp_gain;                 
00202     int *ltp_gain_buffer;           
00203     int32_t **quant_cof;            
00204     int32_t *quant_cof_buffer;      
00205     int32_t **lpc_cof;              
00206     int32_t *lpc_cof_buffer;        
00207     int32_t *lpc_cof_reversed_buffer; 
00208     ALSChannelData **chan_data;     
00209     ALSChannelData *chan_data_buffer; 
00210     int *reverted_channels;         
00211     int32_t *prev_raw_samples;      
00212     int32_t **raw_samples;          
00213     int32_t *raw_buffer;            
00214 } ALSDecContext;
00215 
00216 
00217 typedef struct {
00218     unsigned int block_length;      
00219     unsigned int ra_block;          
00220     int          const_block;       
00221     int32_t      const_val;         
00222     int          js_blocks;         
00223     unsigned int shift_lsbs;        
00224     unsigned int opt_order;         
00225     int          store_prev_samples;
00226     int          *use_ltp;          
00227     int          *ltp_lag;          
00228     int          *ltp_gain;         
00229     int32_t      *quant_cof;        
00230     int32_t      *lpc_cof;          
00231     int32_t      *raw_samples;      
00232     int32_t      *prev_raw_samples; 
00233     int32_t      *raw_other;        
00234 } ALSBlockData;
00235 
00236 
00237 static av_cold void dprint_specific_config(ALSDecContext *ctx)
00238 {
00239 #ifdef DEBUG
00240     AVCodecContext *avctx    = ctx->avctx;
00241     ALSSpecificConfig *sconf = &ctx->sconf;
00242 
00243     dprintf(avctx, "resolution = %i\n",           sconf->resolution);
00244     dprintf(avctx, "floating = %i\n",             sconf->floating);
00245     dprintf(avctx, "frame_length = %i\n",         sconf->frame_length);
00246     dprintf(avctx, "ra_distance = %i\n",          sconf->ra_distance);
00247     dprintf(avctx, "ra_flag = %i\n",              sconf->ra_flag);
00248     dprintf(avctx, "adapt_order = %i\n",          sconf->adapt_order);
00249     dprintf(avctx, "coef_table = %i\n",           sconf->coef_table);
00250     dprintf(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);
00251     dprintf(avctx, "max_order = %i\n",            sconf->max_order);
00252     dprintf(avctx, "block_switching = %i\n",      sconf->block_switching);
00253     dprintf(avctx, "bgmc = %i\n",                 sconf->bgmc);
00254     dprintf(avctx, "sb_part = %i\n",              sconf->sb_part);
00255     dprintf(avctx, "joint_stereo = %i\n",         sconf->joint_stereo);
00256     dprintf(avctx, "mc_coding = %i\n",            sconf->mc_coding);
00257     dprintf(avctx, "chan_config = %i\n",          sconf->chan_config);
00258     dprintf(avctx, "chan_sort = %i\n",            sconf->chan_sort);
00259     dprintf(avctx, "RLSLMS = %i\n",               sconf->rlslms);
00260     dprintf(avctx, "chan_config_info = %i\n",     sconf->chan_config_info);
00261 #endif
00262 }
00263 
00264 
00267 static av_cold int read_specific_config(ALSDecContext *ctx)
00268 {
00269     GetBitContext gb;
00270     uint64_t ht_size;
00271     int i, config_offset, crc_enabled;
00272     MPEG4AudioConfig m4ac;
00273     ALSSpecificConfig *sconf = &ctx->sconf;
00274     AVCodecContext *avctx    = ctx->avctx;
00275     uint32_t als_id, header_size, trailer_size;
00276 
00277     init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8);
00278 
00279     config_offset = ff_mpeg4audio_get_config(&m4ac, avctx->extradata,
00280                                              avctx->extradata_size);
00281 
00282     if (config_offset < 0)
00283         return -1;
00284 
00285     skip_bits_long(&gb, config_offset);
00286 
00287     if (get_bits_left(&gb) < (30 << 3))
00288         return -1;
00289 
00290     // read the fixed items
00291     als_id                      = get_bits_long(&gb, 32);
00292     avctx->sample_rate          = m4ac.sample_rate;
00293     skip_bits_long(&gb, 32); // sample rate already known
00294     sconf->samples              = get_bits_long(&gb, 32);
00295     avctx->channels             = m4ac.channels;
00296     skip_bits(&gb, 16);      // number of channels already knwon
00297     skip_bits(&gb, 3);       // skip file_type
00298     sconf->resolution           = get_bits(&gb, 3);
00299     sconf->floating             = get_bits1(&gb);
00300     skip_bits1(&gb);         // skip msb_first
00301     sconf->frame_length         = get_bits(&gb, 16) + 1;
00302     sconf->ra_distance          = get_bits(&gb, 8);
00303     sconf->ra_flag              = get_bits(&gb, 2);
00304     sconf->adapt_order          = get_bits1(&gb);
00305     sconf->coef_table           = get_bits(&gb, 2);
00306     sconf->long_term_prediction = get_bits1(&gb);
00307     sconf->max_order            = get_bits(&gb, 10);
00308     sconf->block_switching      = get_bits(&gb, 2);
00309     sconf->bgmc                 = get_bits1(&gb);
00310     sconf->sb_part              = get_bits1(&gb);
00311     sconf->joint_stereo         = get_bits1(&gb);
00312     sconf->mc_coding            = get_bits1(&gb);
00313     sconf->chan_config          = get_bits1(&gb);
00314     sconf->chan_sort            = get_bits1(&gb);
00315     crc_enabled                 = get_bits1(&gb);
00316     sconf->rlslms               = get_bits1(&gb);
00317     skip_bits(&gb, 5);       // skip 5 reserved bits
00318     skip_bits1(&gb);         // skip aux_data_enabled
00319 
00320 
00321     // check for ALSSpecificConfig struct
00322     if (als_id != MKBETAG('A','L','S','\0'))
00323         return -1;
00324 
00325     ctx->cur_frame_length = sconf->frame_length;
00326 
00327     // read channel config
00328     if (sconf->chan_config)
00329         sconf->chan_config_info = get_bits(&gb, 16);
00330     // TODO: use this to set avctx->channel_layout
00331 
00332 
00333     // read channel sorting
00334     if (sconf->chan_sort && avctx->channels > 1) {
00335         int chan_pos_bits = av_ceil_log2(avctx->channels);
00336         int bits_needed  = avctx->channels * chan_pos_bits + 7;
00337         if (get_bits_left(&gb) < bits_needed)
00338             return -1;
00339 
00340         if (!(sconf->chan_pos = av_malloc(avctx->channels * sizeof(*sconf->chan_pos))))
00341             return AVERROR(ENOMEM);
00342 
00343         for (i = 0; i < avctx->channels; i++)
00344             sconf->chan_pos[i] = get_bits(&gb, chan_pos_bits);
00345 
00346         align_get_bits(&gb);
00347         // TODO: use this to actually do channel sorting
00348     } else {
00349         sconf->chan_sort = 0;
00350     }
00351 
00352 
00353     // read fixed header and trailer sizes,
00354     // if size = 0xFFFFFFFF then there is no data field!
00355     if (get_bits_left(&gb) < 64)
00356         return -1;
00357 
00358     header_size  = get_bits_long(&gb, 32);
00359     trailer_size = get_bits_long(&gb, 32);
00360     if (header_size  == 0xFFFFFFFF)
00361         header_size  = 0;
00362     if (trailer_size == 0xFFFFFFFF)
00363         trailer_size = 0;
00364 
00365     ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;
00366 
00367 
00368     // skip the header and trailer data
00369     if (get_bits_left(&gb) < ht_size)
00370         return -1;
00371 
00372     if (ht_size > INT32_MAX)
00373         return -1;
00374 
00375     skip_bits_long(&gb, ht_size);
00376 
00377 
00378     // skip the crc data
00379     if (crc_enabled) {
00380         if (get_bits_left(&gb) < 32)
00381             return -1;
00382 
00383         skip_bits_long(&gb, 32);
00384     }
00385 
00386 
00387     // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data)
00388 
00389     dprint_specific_config(ctx);
00390 
00391     return 0;
00392 }
00393 
00394 
00397 static int check_specific_config(ALSDecContext *ctx)
00398 {
00399     ALSSpecificConfig *sconf = &ctx->sconf;
00400     int error = 0;
00401 
00402     // report unsupported feature and set error value
00403     #define MISSING_ERR(cond, str, errval)              \
00404     {                                                   \
00405         if (cond) {                                     \
00406             av_log_missing_feature(ctx->avctx, str, 0); \
00407             error = errval;                             \
00408         }                                               \
00409     }
00410 
00411     MISSING_ERR(sconf->floating,             "Floating point decoding",     -1);
00412     MISSING_ERR(sconf->rlslms,               "Adaptive RLS-LMS prediction", -1);
00413     MISSING_ERR(sconf->chan_sort,            "Channel sorting",              0);
00414 
00415     return error;
00416 }
00417 
00418 
00422 static void parse_bs_info(const uint32_t bs_info, unsigned int n,
00423                           unsigned int div, unsigned int **div_blocks,
00424                           unsigned int *num_blocks)
00425 {
00426     if (n < 31 && ((bs_info << n) & 0x40000000)) {
00427         // if the level is valid and the investigated bit n is set
00428         // then recursively check both children at bits (2n+1) and (2n+2)
00429         n   *= 2;
00430         div += 1;
00431         parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);
00432         parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);
00433     } else {
00434         // else the bit is not set or the last level has been reached
00435         // (bit implicitly not set)
00436         **div_blocks = div;
00437         (*div_blocks)++;
00438         (*num_blocks)++;
00439     }
00440 }
00441 
00442 
00445 static int32_t decode_rice(GetBitContext *gb, unsigned int k)
00446 {
00447     int max = get_bits_left(gb) - k;
00448     int q   = get_unary(gb, 0, max);
00449     int r   = k ? get_bits1(gb) : !(q & 1);
00450 
00451     if (k > 1) {
00452         q <<= (k - 1);
00453         q  += get_bits_long(gb, k - 1);
00454     } else if (!k) {
00455         q >>= 1;
00456     }
00457     return r ? q : ~q;
00458 }
00459 
00460 
00463 static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)
00464 {
00465     int i, j;
00466 
00467     for (i = 0, j = k - 1; i < j; i++, j--) {
00468         int tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
00469         cof[j]  += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);
00470         cof[i]  += tmp1;
00471     }
00472     if (i == j)
00473         cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
00474 
00475     cof[k] = par[k];
00476 }
00477 
00478 
00483 static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
00484                             uint32_t *bs_info)
00485 {
00486     ALSSpecificConfig *sconf     = &ctx->sconf;
00487     GetBitContext *gb            = &ctx->gb;
00488     unsigned int *ptr_div_blocks = div_blocks;
00489     unsigned int b;
00490 
00491     if (sconf->block_switching) {
00492         unsigned int bs_info_len = 1 << (sconf->block_switching + 2);
00493         *bs_info = get_bits_long(gb, bs_info_len);
00494         *bs_info <<= (32 - bs_info_len);
00495     }
00496 
00497     ctx->num_blocks = 0;
00498     parse_bs_info(*bs_info, 0, 0, &ptr_div_blocks, &ctx->num_blocks);
00499 
00500     // The last frame may have an overdetermined block structure given in
00501     // the bitstream. In that case the defined block structure would need
00502     // more samples than available to be consistent.
00503     // The block structure is actually used but the block sizes are adapted
00504     // to fit the actual number of available samples.
00505     // Example: 5 samples, 2nd level block sizes: 2 2 2 2.
00506     // This results in the actual block sizes:    2 2 1 0.
00507     // This is not specified in 14496-3 but actually done by the reference
00508     // codec RM22 revision 2.
00509     // This appears to happen in case of an odd number of samples in the last
00510     // frame which is actually not allowed by the block length switching part
00511     // of 14496-3.
00512     // The ALS conformance files feature an odd number of samples in the last
00513     // frame.
00514 
00515     for (b = 0; b < ctx->num_blocks; b++)
00516         div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];
00517 
00518     if (ctx->cur_frame_length != ctx->sconf.frame_length) {
00519         unsigned int remaining = ctx->cur_frame_length;
00520 
00521         for (b = 0; b < ctx->num_blocks; b++) {
00522             if (remaining <= div_blocks[b]) {
00523                 div_blocks[b] = remaining;
00524                 ctx->num_blocks = b + 1;
00525                 break;
00526             }
00527 
00528             remaining -= div_blocks[b];
00529         }
00530     }
00531 }
00532 
00533 
00536 static void read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00537 {
00538     ALSSpecificConfig *sconf = &ctx->sconf;
00539     AVCodecContext *avctx    = ctx->avctx;
00540     GetBitContext *gb        = &ctx->gb;
00541 
00542     bd->const_val    = 0;
00543     bd->const_block  = get_bits1(gb);    // 1 = constant value, 0 = zero block (silence)
00544     bd->js_blocks    = get_bits1(gb);
00545 
00546     // skip 5 reserved bits
00547     skip_bits(gb, 5);
00548 
00549     if (bd->const_block) {
00550         unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;
00551         bd->const_val = get_sbits_long(gb, const_val_bits);
00552     }
00553 
00554     // ensure constant block decoding by reusing this field
00555     bd->const_block = 1;
00556 }
00557 
00558 
00561 static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00562 {
00563     int      smp = bd->block_length;
00564     int32_t  val = bd->const_val;
00565     int32_t *dst = bd->raw_samples;
00566 
00567     // write raw samples into buffer
00568     for (; smp; smp--)
00569         *dst++ = val;
00570 }
00571 
00572 
00575 static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00576 {
00577     ALSSpecificConfig *sconf = &ctx->sconf;
00578     AVCodecContext *avctx    = ctx->avctx;
00579     GetBitContext *gb        = &ctx->gb;
00580     unsigned int k;
00581     unsigned int s[8];
00582     unsigned int sx[8];
00583     unsigned int sub_blocks, log2_sub_blocks, sb_length;
00584     unsigned int start      = 0;
00585     unsigned int opt_order;
00586     int          sb;
00587     int32_t      *quant_cof = bd->quant_cof;
00588     int32_t      *current_res;
00589 
00590 
00591     // ensure variable block decoding by reusing this field
00592     bd->const_block = 0;
00593 
00594     bd->opt_order   = 1;
00595     bd->js_blocks   = get_bits1(gb);
00596 
00597     opt_order       = bd->opt_order;
00598 
00599     // determine the number of subblocks for entropy decoding
00600     if (!sconf->bgmc && !sconf->sb_part) {
00601         log2_sub_blocks = 0;
00602     } else {
00603         if (sconf->bgmc && sconf->sb_part)
00604             log2_sub_blocks = get_bits(gb, 2);
00605         else
00606             log2_sub_blocks = 2 * get_bits1(gb);
00607     }
00608 
00609     sub_blocks = 1 << log2_sub_blocks;
00610 
00611     // do not continue in case of a damaged stream since
00612     // block_length must be evenly divisible by sub_blocks
00613     if (bd->block_length & (sub_blocks - 1)) {
00614         av_log(avctx, AV_LOG_WARNING,
00615                "Block length is not evenly divisible by the number of subblocks.\n");
00616         return -1;
00617     }
00618 
00619     sb_length = bd->block_length >> log2_sub_blocks;
00620 
00621     if (sconf->bgmc) {
00622         s[0] = get_bits(gb, 8 + (sconf->resolution > 1));
00623         for (k = 1; k < sub_blocks; k++)
00624             s[k] = s[k - 1] + decode_rice(gb, 2);
00625 
00626         for (k = 0; k < sub_blocks; k++) {
00627             sx[k]   = s[k] & 0x0F;
00628             s [k] >>= 4;
00629         }
00630     } else {
00631         s[0] = get_bits(gb, 4 + (sconf->resolution > 1));
00632         for (k = 1; k < sub_blocks; k++)
00633             s[k] = s[k - 1] + decode_rice(gb, 0);
00634     }
00635 
00636     if (get_bits1(gb))
00637         bd->shift_lsbs = get_bits(gb, 4) + 1;
00638 
00639     bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || bd->shift_lsbs;
00640 
00641 
00642     if (!sconf->rlslms) {
00643         if (sconf->adapt_order) {
00644             int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
00645                                                 2, sconf->max_order + 1));
00646             bd->opt_order        = get_bits(gb, opt_order_length);
00647         } else {
00648             bd->opt_order = sconf->max_order;
00649         }
00650 
00651         opt_order = bd->opt_order;
00652 
00653         if (opt_order) {
00654             int add_base;
00655 
00656             if (sconf->coef_table == 3) {
00657                 add_base = 0x7F;
00658 
00659                 // read coefficient 0
00660                 quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];
00661 
00662                 // read coefficient 1
00663                 if (opt_order > 1)
00664                     quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];
00665 
00666                 // read coefficients 2 to opt_order
00667                 for (k = 2; k < opt_order; k++)
00668                     quant_cof[k] = get_bits(gb, 7);
00669             } else {
00670                 int k_max;
00671                 add_base = 1;
00672 
00673                 // read coefficient 0 to 19
00674                 k_max = FFMIN(opt_order, 20);
00675                 for (k = 0; k < k_max; k++) {
00676                     int rice_param = parcor_rice_table[sconf->coef_table][k][1];
00677                     int offset     = parcor_rice_table[sconf->coef_table][k][0];
00678                     quant_cof[k] = decode_rice(gb, rice_param) + offset;
00679                 }
00680 
00681                 // read coefficients 20 to 126
00682                 k_max = FFMIN(opt_order, 127);
00683                 for (; k < k_max; k++)
00684                     quant_cof[k] = decode_rice(gb, 2) + (k & 1);
00685 
00686                 // read coefficients 127 to opt_order
00687                 for (; k < opt_order; k++)
00688                     quant_cof[k] = decode_rice(gb, 1);
00689 
00690                 quant_cof[0] = 32 * parcor_scaled_values[quant_cof[0] + 64];
00691 
00692                 if (opt_order > 1)
00693                     quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];
00694             }
00695 
00696             for (k = 2; k < opt_order; k++)
00697                 quant_cof[k] = (quant_cof[k] << 14) + (add_base << 13);
00698         }
00699     }
00700 
00701     // read LTP gain and lag values
00702     if (sconf->long_term_prediction) {
00703         *bd->use_ltp = get_bits1(gb);
00704 
00705         if (*bd->use_ltp) {
00706             int r, c;
00707 
00708             bd->ltp_gain[0]   = decode_rice(gb, 1) << 3;
00709             bd->ltp_gain[1]   = decode_rice(gb, 2) << 3;
00710 
00711             r                 = get_unary(gb, 0, 4);
00712             c                 = get_bits(gb, 2);
00713             bd->ltp_gain[2]   = ltp_gain_values[r][c];
00714 
00715             bd->ltp_gain[3]   = decode_rice(gb, 2) << 3;
00716             bd->ltp_gain[4]   = decode_rice(gb, 1) << 3;
00717 
00718             *bd->ltp_lag      = get_bits(gb, ctx->ltp_lag_length);
00719             *bd->ltp_lag     += FFMAX(4, opt_order + 1);
00720         }
00721     }
00722 
00723     // read first value and residuals in case of a random access block
00724     if (bd->ra_block) {
00725         if (opt_order)
00726             bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);
00727         if (opt_order > 1)
00728             bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));
00729         if (opt_order > 2)
00730             bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));
00731 
00732         start = FFMIN(opt_order, 3);
00733     }
00734 
00735     // read all residuals
00736     if (sconf->bgmc) {
00737         unsigned int delta[sub_blocks];
00738         unsigned int k    [sub_blocks];
00739         unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);
00740         unsigned int i = start;
00741 
00742         // read most significant bits
00743         unsigned int high;
00744         unsigned int low;
00745         unsigned int value;
00746 
00747         ff_bgmc_decode_init(gb, &high, &low, &value);
00748 
00749         current_res = bd->raw_samples + start;
00750 
00751         for (sb = 0; sb < sub_blocks; sb++, i = 0) {
00752             k    [sb] = s[sb] > b ? s[sb] - b : 0;
00753             delta[sb] = 5 - s[sb] + k[sb];
00754 
00755             ff_bgmc_decode(gb, sb_length, current_res,
00756                         delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);
00757 
00758             current_res += sb_length;
00759         }
00760 
00761         ff_bgmc_decode_end(gb);
00762 
00763 
00764         // read least significant bits and tails
00765         i = start;
00766         current_res = bd->raw_samples + start;
00767 
00768         for (sb = 0; sb < sub_blocks; sb++, i = 0) {
00769             unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];
00770             unsigned int cur_k         = k[sb];
00771             unsigned int cur_s         = s[sb];
00772 
00773             for (; i < sb_length; i++) {
00774                 int32_t res = *current_res;
00775 
00776                 if (res == cur_tail_code) {
00777                     unsigned int max_msb =   (2 + (sx[sb] > 2) + (sx[sb] > 10))
00778                                           << (5 - delta[sb]);
00779 
00780                     res = decode_rice(gb, cur_s);
00781 
00782                     if (res >= 0) {
00783                         res += (max_msb    ) << cur_k;
00784                     } else {
00785                         res -= (max_msb - 1) << cur_k;
00786                     }
00787                 } else {
00788                     if (res > cur_tail_code)
00789                         res--;
00790 
00791                     if (res & 1)
00792                         res = -res;
00793 
00794                     res >>= 1;
00795 
00796                     if (cur_k) {
00797                         res <<= cur_k;
00798                         res  |= get_bits_long(gb, cur_k);
00799                     }
00800                 }
00801 
00802                 *current_res++ = res;
00803             }
00804         }
00805     } else {
00806         current_res = bd->raw_samples + start;
00807 
00808         for (sb = 0; sb < sub_blocks; sb++, start = 0)
00809             for (; start < sb_length; start++)
00810                 *current_res++ = decode_rice(gb, s[sb]);
00811      }
00812 
00813     if (!sconf->mc_coding || ctx->js_switch)
00814         align_get_bits(gb);
00815 
00816     return 0;
00817 }
00818 
00819 
00822 static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
00823 {
00824     ALSSpecificConfig *sconf = &ctx->sconf;
00825     unsigned int block_length = bd->block_length;
00826     unsigned int smp = 0;
00827     unsigned int k;
00828     int opt_order             = bd->opt_order;
00829     int sb;
00830     int64_t y;
00831     int32_t *quant_cof        = bd->quant_cof;
00832     int32_t *lpc_cof          = bd->lpc_cof;
00833     int32_t *raw_samples      = bd->raw_samples;
00834     int32_t *raw_samples_end  = bd->raw_samples + bd->block_length;
00835     int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;
00836 
00837     // reverse long-term prediction
00838     if (*bd->use_ltp) {
00839         int ltp_smp;
00840 
00841         for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {
00842             int center = ltp_smp - *bd->ltp_lag;
00843             int begin  = FFMAX(0, center - 2);
00844             int end    = center + 3;
00845             int tab    = 5 - (end - begin);
00846             int base;
00847 
00848             y = 1 << 6;
00849 
00850             for (base = begin; base < end; base++, tab++)
00851                 y += MUL64(bd->ltp_gain[tab], raw_samples[base]);
00852 
00853             raw_samples[ltp_smp] += y >> 7;
00854         }
00855     }
00856 
00857     // reconstruct all samples from residuals
00858     if (bd->ra_block) {
00859         for (smp = 0; smp < opt_order; smp++) {
00860             y = 1 << 19;
00861 
00862             for (sb = 0; sb < smp; sb++)
00863                 y += MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);
00864 
00865             *raw_samples++ -= y >> 20;
00866             parcor_to_lpc(smp, quant_cof, lpc_cof);
00867         }
00868     } else {
00869         for (k = 0; k < opt_order; k++)
00870             parcor_to_lpc(k, quant_cof, lpc_cof);
00871 
00872         // store previous samples in case that they have to be altered
00873         if (bd->store_prev_samples)
00874             memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,
00875                    sizeof(*bd->prev_raw_samples) * sconf->max_order);
00876 
00877         // reconstruct difference signal for prediction (joint-stereo)
00878         if (bd->js_blocks && bd->raw_other) {
00879             int32_t *left, *right;
00880 
00881             if (bd->raw_other > raw_samples) {  // D = R - L
00882                 left  = raw_samples;
00883                 right = bd->raw_other;
00884             } else {                                // D = R - L
00885                 left  = bd->raw_other;
00886                 right = raw_samples;
00887             }
00888 
00889             for (sb = -1; sb >= -sconf->max_order; sb--)
00890                 raw_samples[sb] = right[sb] - left[sb];
00891         }
00892 
00893         // reconstruct shifted signal
00894         if (bd->shift_lsbs)
00895             for (sb = -1; sb >= -sconf->max_order; sb--)
00896                 raw_samples[sb] >>= bd->shift_lsbs;
00897     }
00898 
00899     // reverse linear prediction coefficients for efficiency
00900     lpc_cof = lpc_cof + opt_order;
00901 
00902     for (sb = 0; sb < opt_order; sb++)
00903         lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];
00904 
00905     // reconstruct raw samples
00906     raw_samples = bd->raw_samples + smp;
00907     lpc_cof     = lpc_cof_reversed + opt_order;
00908 
00909     for (; raw_samples < raw_samples_end; raw_samples++) {
00910         y = 1 << 19;
00911 
00912         for (sb = -opt_order; sb < 0; sb++)
00913             y += MUL64(lpc_cof[sb], raw_samples[sb]);
00914 
00915         *raw_samples -= y >> 20;
00916     }
00917 
00918     raw_samples = bd->raw_samples;
00919 
00920     // restore previous samples in case that they have been altered
00921     if (bd->store_prev_samples)
00922         memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,
00923                sizeof(*raw_samples) * sconf->max_order);
00924 
00925     return 0;
00926 }
00927 
00928 
00931 static int read_block(ALSDecContext *ctx, ALSBlockData *bd)
00932 {
00933     GetBitContext *gb        = &ctx->gb;
00934 
00935     // read block type flag and read the samples accordingly
00936     if (get_bits1(gb)) {
00937         if (read_var_block_data(ctx, bd))
00938             return -1;
00939     } else {
00940         read_const_block_data(ctx, bd);
00941     }
00942 
00943     return 0;
00944 }
00945 
00946 
00949 static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)
00950 {
00951     unsigned int smp;
00952 
00953     // read block type flag and read the samples accordingly
00954     if (bd->const_block)
00955         decode_const_block_data(ctx, bd);
00956     else if (decode_var_block_data(ctx, bd))
00957         return -1;
00958 
00959     // TODO: read RLSLMS extension data
00960 
00961     if (bd->shift_lsbs)
00962         for (smp = 0; smp < bd->block_length; smp++)
00963             bd->raw_samples[smp] <<= bd->shift_lsbs;
00964 
00965     return 0;
00966 }
00967 
00968 
00971 static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)
00972 {
00973     int ret;
00974 
00975     ret = read_block(ctx, bd);
00976 
00977     if (ret)
00978         return ret;
00979 
00980     ret = decode_block(ctx, bd);
00981 
00982     return ret;
00983 }
00984 
00985 
00989 static void zero_remaining(unsigned int b, unsigned int b_max,
00990                            const unsigned int *div_blocks, int32_t *buf)
00991 {
00992     unsigned int count = 0;
00993 
00994     while (b < b_max)
00995         count += div_blocks[b];
00996 
00997     if (count)
00998         memset(buf, 0, sizeof(*buf) * count);
00999 }
01000 
01001 
01004 static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,
01005                              unsigned int c, const unsigned int *div_blocks,
01006                              unsigned int *js_blocks)
01007 {
01008     unsigned int b;
01009     ALSBlockData bd;
01010 
01011     memset(&bd, 0, sizeof(ALSBlockData));
01012 
01013     bd.ra_block         = ra_frame;
01014     bd.use_ltp          = ctx->use_ltp;
01015     bd.ltp_lag          = ctx->ltp_lag;
01016     bd.ltp_gain         = ctx->ltp_gain[0];
01017     bd.quant_cof        = ctx->quant_cof[0];
01018     bd.lpc_cof          = ctx->lpc_cof[0];
01019     bd.prev_raw_samples = ctx->prev_raw_samples;
01020     bd.raw_samples      = ctx->raw_samples[c];
01021 
01022 
01023     for (b = 0; b < ctx->num_blocks; b++) {
01024         bd.shift_lsbs       = 0;
01025         bd.block_length     = div_blocks[b];
01026 
01027         if (read_decode_block(ctx, &bd)) {
01028             // damaged block, write zero for the rest of the frame
01029             zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);
01030             return -1;
01031         }
01032         bd.raw_samples += div_blocks[b];
01033         bd.ra_block     = 0;
01034     }
01035 
01036     return 0;
01037 }
01038 
01039 
01042 static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,
01043                          unsigned int c, const unsigned int *div_blocks,
01044                          unsigned int *js_blocks)
01045 {
01046     ALSSpecificConfig *sconf = &ctx->sconf;
01047     unsigned int offset = 0;
01048     unsigned int b;
01049     ALSBlockData bd[2];
01050 
01051     memset(bd, 0, 2 * sizeof(ALSBlockData));
01052 
01053     bd[0].ra_block         = ra_frame;
01054     bd[0].use_ltp          = ctx->use_ltp;
01055     bd[0].ltp_lag          = ctx->ltp_lag;
01056     bd[0].ltp_gain         = ctx->ltp_gain[0];
01057     bd[0].quant_cof        = ctx->quant_cof[0];
01058     bd[0].lpc_cof          = ctx->lpc_cof[0];
01059     bd[0].prev_raw_samples = ctx->prev_raw_samples;
01060     bd[0].js_blocks        = *js_blocks;
01061 
01062     bd[1].ra_block         = ra_frame;
01063     bd[1].use_ltp          = ctx->use_ltp;
01064     bd[1].ltp_lag          = ctx->ltp_lag;
01065     bd[1].ltp_gain         = ctx->ltp_gain[0];
01066     bd[1].quant_cof        = ctx->quant_cof[0];
01067     bd[1].lpc_cof          = ctx->lpc_cof[0];
01068     bd[1].prev_raw_samples = ctx->prev_raw_samples;
01069     bd[1].js_blocks        = *(js_blocks + 1);
01070 
01071     // decode all blocks
01072     for (b = 0; b < ctx->num_blocks; b++) {
01073         unsigned int s;
01074 
01075         bd[0].shift_lsbs   = 0;
01076         bd[1].shift_lsbs   = 0;
01077 
01078         bd[0].block_length = div_blocks[b];
01079         bd[1].block_length = div_blocks[b];
01080 
01081         bd[0].raw_samples  = ctx->raw_samples[c    ] + offset;
01082         bd[1].raw_samples  = ctx->raw_samples[c + 1] + offset;
01083 
01084         bd[0].raw_other    = bd[1].raw_samples;
01085         bd[1].raw_other    = bd[0].raw_samples;
01086 
01087         if(read_decode_block(ctx, &bd[0]) || read_decode_block(ctx, &bd[1])) {
01088             // damaged block, write zero for the rest of the frame
01089             zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);
01090             zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);
01091             return -1;
01092         }
01093 
01094         // reconstruct joint-stereo blocks
01095         if (bd[0].js_blocks) {
01096             if (bd[1].js_blocks)
01097                 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair!\n");
01098 
01099             for (s = 0; s < div_blocks[b]; s++)
01100                 bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];
01101         } else if (bd[1].js_blocks) {
01102             for (s = 0; s < div_blocks[b]; s++)
01103                 bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];
01104         }
01105 
01106         offset  += div_blocks[b];
01107         bd[0].ra_block = 0;
01108         bd[1].ra_block = 0;
01109     }
01110 
01111     // store carryover raw samples,
01112     // the others channel raw samples are stored by the calling function.
01113     memmove(ctx->raw_samples[c] - sconf->max_order,
01114             ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01115             sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01116 
01117     return 0;
01118 }
01119 
01120 
01123 static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)
01124 {
01125     GetBitContext *gb       = &ctx->gb;
01126     ALSChannelData *current = cd;
01127     unsigned int channels   = ctx->avctx->channels;
01128     int entries             = 0;
01129 
01130     while (entries < channels && !(current->stop_flag = get_bits1(gb))) {
01131         current->master_channel = get_bits_long(gb, av_ceil_log2(channels));
01132 
01133         if (current->master_channel >= channels) {
01134             av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel!\n");
01135             return -1;
01136         }
01137 
01138         if (current->master_channel != c) {
01139             current->time_diff_flag = get_bits1(gb);
01140             current->weighting[0]   = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01141             current->weighting[1]   = mcc_weightings[av_clip(decode_rice(gb, 2) + 14, 0, 32)];
01142             current->weighting[2]   = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01143 
01144             if (current->time_diff_flag) {
01145                 current->weighting[3] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01146                 current->weighting[4] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01147                 current->weighting[5] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
01148 
01149                 current->time_diff_sign  = get_bits1(gb);
01150                 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;
01151             }
01152         }
01153 
01154         current++;
01155         entries++;
01156     }
01157 
01158     if (entries == channels) {
01159         av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data!\n");
01160         return -1;
01161     }
01162 
01163     align_get_bits(gb);
01164     return 0;
01165 }
01166 
01167 
01170 static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
01171                                        ALSChannelData **cd, int *reverted,
01172                                        unsigned int offset, int c)
01173 {
01174     ALSChannelData *ch = cd[c];
01175     unsigned int   dep = 0;
01176     unsigned int channels = ctx->avctx->channels;
01177 
01178     if (reverted[c])
01179         return 0;
01180 
01181     reverted[c] = 1;
01182 
01183     while (dep < channels && !ch[dep].stop_flag) {
01184         revert_channel_correlation(ctx, bd, cd, reverted, offset,
01185                                    ch[dep].master_channel);
01186 
01187         dep++;
01188     }
01189 
01190     if (dep == channels) {
01191         av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation!\n");
01192         return -1;
01193     }
01194 
01195     bd->use_ltp     = ctx->use_ltp + c;
01196     bd->ltp_lag     = ctx->ltp_lag + c;
01197     bd->ltp_gain    = ctx->ltp_gain[c];
01198     bd->lpc_cof     = ctx->lpc_cof[c];
01199     bd->quant_cof   = ctx->quant_cof[c];
01200     bd->raw_samples = ctx->raw_samples[c] + offset;
01201 
01202     dep = 0;
01203     while (!ch[dep].stop_flag) {
01204         unsigned int smp;
01205         unsigned int begin = 1;
01206         unsigned int end   = bd->block_length - 1;
01207         int64_t y;
01208         int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;
01209 
01210         if (ch[dep].time_diff_flag) {
01211             int t = ch[dep].time_diff_index;
01212 
01213             if (ch[dep].time_diff_sign) {
01214                 t      = -t;
01215                 begin -= t;
01216             } else {
01217                 end   -= t;
01218             }
01219 
01220             for (smp = begin; smp < end; smp++) {
01221                 y  = (1 << 6) +
01222                      MUL64(ch[dep].weighting[0], master[smp - 1    ]) +
01223                      MUL64(ch[dep].weighting[1], master[smp        ]) +
01224                      MUL64(ch[dep].weighting[2], master[smp + 1    ]) +
01225                      MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
01226                      MUL64(ch[dep].weighting[4], master[smp     + t]) +
01227                      MUL64(ch[dep].weighting[5], master[smp + 1 + t]);
01228 
01229                 bd->raw_samples[smp] += y >> 7;
01230             }
01231         } else {
01232             for (smp = begin; smp < end; smp++) {
01233                 y  = (1 << 6) +
01234                      MUL64(ch[dep].weighting[0], master[smp - 1]) +
01235                      MUL64(ch[dep].weighting[1], master[smp    ]) +
01236                      MUL64(ch[dep].weighting[2], master[smp + 1]);
01237 
01238                 bd->raw_samples[smp] += y >> 7;
01239             }
01240         }
01241 
01242         dep++;
01243     }
01244 
01245     return 0;
01246 }
01247 
01248 
01251 static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
01252 {
01253     ALSSpecificConfig *sconf = &ctx->sconf;
01254     AVCodecContext *avctx    = ctx->avctx;
01255     GetBitContext *gb = &ctx->gb;
01256     unsigned int div_blocks[32];                
01257     unsigned int c;
01258     unsigned int js_blocks[2];
01259 
01260     uint32_t bs_info = 0;
01261 
01262     // skip the size of the ra unit if present in the frame
01263     if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)
01264         skip_bits_long(gb, 32);
01265 
01266     if (sconf->mc_coding && sconf->joint_stereo) {
01267         ctx->js_switch = get_bits1(gb);
01268         align_get_bits(gb);
01269     }
01270 
01271     if (!sconf->mc_coding || ctx->js_switch) {
01272         int independent_bs = !sconf->joint_stereo;
01273 
01274         for (c = 0; c < avctx->channels; c++) {
01275             js_blocks[0] = 0;
01276             js_blocks[1] = 0;
01277 
01278             get_block_sizes(ctx, div_blocks, &bs_info);
01279 
01280             // if joint_stereo and block_switching is set, independent decoding
01281             // is signaled via the first bit of bs_info
01282             if (sconf->joint_stereo && sconf->block_switching)
01283                 if (bs_info >> 31)
01284                     independent_bs = 2;
01285 
01286             // if this is the last channel, it has to be decoded independently
01287             if (c == avctx->channels - 1)
01288                 independent_bs = 1;
01289 
01290             if (independent_bs) {
01291                 if (decode_blocks_ind(ctx, ra_frame, c, div_blocks, js_blocks))
01292                     return -1;
01293 
01294                 independent_bs--;
01295             } else {
01296                 if (decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks))
01297                     return -1;
01298 
01299                 c++;
01300             }
01301 
01302             // store carryover raw samples
01303             memmove(ctx->raw_samples[c] - sconf->max_order,
01304                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01305                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01306         }
01307     } else { // multi-channel coding
01308         ALSBlockData   bd;
01309         int            b;
01310         int            *reverted_channels = ctx->reverted_channels;
01311         unsigned int   offset             = 0;
01312 
01313         for (c = 0; c < avctx->channels; c++)
01314             if (ctx->chan_data[c] < ctx->chan_data_buffer) {
01315                 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data!\n");
01316                 return -1;
01317             }
01318 
01319         memset(&bd,               0, sizeof(ALSBlockData));
01320         memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);
01321 
01322         bd.ra_block         = ra_frame;
01323         bd.prev_raw_samples = ctx->prev_raw_samples;
01324 
01325         get_block_sizes(ctx, div_blocks, &bs_info);
01326 
01327         for (b = 0; b < ctx->num_blocks; b++) {
01328             bd.shift_lsbs   = 0;
01329             bd.block_length = div_blocks[b];
01330 
01331             for (c = 0; c < avctx->channels; c++) {
01332                 bd.use_ltp     = ctx->use_ltp + c;
01333                 bd.ltp_lag     = ctx->ltp_lag + c;
01334                 bd.ltp_gain    = ctx->ltp_gain[c];
01335                 bd.lpc_cof     = ctx->lpc_cof[c];
01336                 bd.quant_cof   = ctx->quant_cof[c];
01337                 bd.raw_samples = ctx->raw_samples[c] + offset;
01338                 bd.raw_other   = NULL;
01339 
01340                 read_block(ctx, &bd);
01341                 if (read_channel_data(ctx, ctx->chan_data[c], c))
01342                     return -1;
01343             }
01344 
01345             for (c = 0; c < avctx->channels; c++)
01346                 if (revert_channel_correlation(ctx, &bd, ctx->chan_data,
01347                                                reverted_channels, offset, c))
01348                     return -1;
01349 
01350             for (c = 0; c < avctx->channels; c++) {
01351                 bd.use_ltp     = ctx->use_ltp + c;
01352                 bd.ltp_lag     = ctx->ltp_lag + c;
01353                 bd.ltp_gain    = ctx->ltp_gain[c];
01354                 bd.lpc_cof     = ctx->lpc_cof[c];
01355                 bd.quant_cof   = ctx->quant_cof[c];
01356                 bd.raw_samples = ctx->raw_samples[c] + offset;
01357                 decode_block(ctx, &bd);
01358             }
01359 
01360             memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));
01361             offset      += div_blocks[b];
01362             bd.ra_block  = 0;
01363         }
01364 
01365         // store carryover raw samples
01366         for (c = 0; c < avctx->channels; c++)
01367             memmove(ctx->raw_samples[c] - sconf->max_order,
01368                     ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
01369                     sizeof(*ctx->raw_samples[c]) * sconf->max_order);
01370     }
01371 
01372     // TODO: read_diff_float_data
01373 
01374     return 0;
01375 }
01376 
01377 
01380 static int decode_frame(AVCodecContext *avctx,
01381                         void *data, int *data_size,
01382                         AVPacket *avpkt)
01383 {
01384     ALSDecContext *ctx       = avctx->priv_data;
01385     ALSSpecificConfig *sconf = &ctx->sconf;
01386     const uint8_t *buffer    = avpkt->data;
01387     int buffer_size          = avpkt->size;
01388     int invalid_frame, size;
01389     unsigned int c, sample, ra_frame, bytes_read, shift;
01390 
01391     init_get_bits(&ctx->gb, buffer, buffer_size * 8);
01392 
01393     // In the case that the distance between random access frames is set to zero
01394     // (sconf->ra_distance == 0) no frame is treated as a random access frame.
01395     // For the first frame, if prediction is used, all samples used from the
01396     // previous frame are assumed to be zero.
01397     ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);
01398 
01399     // the last frame to decode might have a different length
01400     if (sconf->samples != 0xFFFFFFFF)
01401         ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,
01402                                       sconf->frame_length);
01403     else
01404         ctx->cur_frame_length = sconf->frame_length;
01405 
01406     // decode the frame data
01407     if ((invalid_frame = read_frame_data(ctx, ra_frame) < 0))
01408         av_log(ctx->avctx, AV_LOG_WARNING,
01409                "Reading frame data failed. Skipping RA unit.\n");
01410 
01411     ctx->frame_id++;
01412 
01413     // check for size of decoded data
01414     size = ctx->cur_frame_length * avctx->channels *
01415            (av_get_bits_per_sample_format(avctx->sample_fmt) >> 3);
01416 
01417     if (size > *data_size) {
01418         av_log(avctx, AV_LOG_ERROR, "Decoded data exceeds buffer size.\n");
01419         return -1;
01420     }
01421 
01422     *data_size = size;
01423 
01424     // transform decoded frame into output format
01425     #define INTERLEAVE_OUTPUT(bps)                                 \
01426     {                                                              \
01427         int##bps##_t *dest = (int##bps##_t*) data;                 \
01428         shift = bps - ctx->avctx->bits_per_raw_sample;             \
01429         for (sample = 0; sample < ctx->cur_frame_length; sample++) \
01430             for (c = 0; c < avctx->channels; c++)                  \
01431                 *dest++ = ctx->raw_samples[c][sample] << shift;    \
01432     }
01433 
01434     if (ctx->avctx->bits_per_raw_sample <= 16) {
01435         INTERLEAVE_OUTPUT(16)
01436     } else {
01437         INTERLEAVE_OUTPUT(32)
01438     }
01439 
01440     bytes_read = invalid_frame ? buffer_size :
01441                                  (get_bits_count(&ctx->gb) + 7) >> 3;
01442 
01443     return bytes_read;
01444 }
01445 
01446 
01449 static av_cold int decode_end(AVCodecContext *avctx)
01450 {
01451     ALSDecContext *ctx = avctx->priv_data;
01452 
01453     av_freep(&ctx->sconf.chan_pos);
01454 
01455     ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);
01456 
01457     av_freep(&ctx->use_ltp);
01458     av_freep(&ctx->ltp_lag);
01459     av_freep(&ctx->ltp_gain);
01460     av_freep(&ctx->ltp_gain_buffer);
01461     av_freep(&ctx->quant_cof);
01462     av_freep(&ctx->lpc_cof);
01463     av_freep(&ctx->quant_cof_buffer);
01464     av_freep(&ctx->lpc_cof_buffer);
01465     av_freep(&ctx->lpc_cof_reversed_buffer);
01466     av_freep(&ctx->prev_raw_samples);
01467     av_freep(&ctx->raw_samples);
01468     av_freep(&ctx->raw_buffer);
01469     av_freep(&ctx->chan_data);
01470     av_freep(&ctx->chan_data_buffer);
01471     av_freep(&ctx->reverted_channels);
01472 
01473     return 0;
01474 }
01475 
01476 
01479 static av_cold int decode_init(AVCodecContext *avctx)
01480 {
01481     unsigned int c;
01482     unsigned int channel_size;
01483     int num_buffers;
01484     ALSDecContext *ctx = avctx->priv_data;
01485     ALSSpecificConfig *sconf = &ctx->sconf;
01486     ctx->avctx = avctx;
01487 
01488     if (!avctx->extradata) {
01489         av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");
01490         return -1;
01491     }
01492 
01493     if (read_specific_config(ctx)) {
01494         av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");
01495         decode_end(avctx);
01496         return -1;
01497     }
01498 
01499     if (check_specific_config(ctx)) {
01500         decode_end(avctx);
01501         return -1;
01502     }
01503 
01504     if (sconf->bgmc)
01505         ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);
01506 
01507     if (sconf->floating) {
01508         avctx->sample_fmt          = SAMPLE_FMT_FLT;
01509         avctx->bits_per_raw_sample = 32;
01510     } else {
01511         avctx->sample_fmt          = sconf->resolution > 1
01512                                      ? SAMPLE_FMT_S32 : SAMPLE_FMT_S16;
01513         avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;
01514     }
01515 
01516     // set maximum Rice parameter for progressive decoding based on resolution
01517     // This is not specified in 14496-3 but actually done by the reference
01518     // codec RM22 revision 2.
01519     ctx->s_max = sconf->resolution > 1 ? 31 : 15;
01520 
01521     // set lag value for long-term prediction
01522     ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +
01523                               (avctx->sample_rate >= 192000);
01524 
01525     // allocate quantized parcor coefficient buffer
01526     num_buffers = sconf->mc_coding ? avctx->channels : 1;
01527 
01528     ctx->quant_cof        = av_malloc(sizeof(*ctx->quant_cof) * num_buffers);
01529     ctx->lpc_cof          = av_malloc(sizeof(*ctx->lpc_cof)   * num_buffers);
01530     ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) *
01531                                       num_buffers * sconf->max_order);
01532     ctx->lpc_cof_buffer   = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
01533                                       num_buffers * sconf->max_order);
01534     ctx->lpc_cof_reversed_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
01535                                              sconf->max_order);
01536 
01537     if (!ctx->quant_cof              || !ctx->lpc_cof        ||
01538         !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||
01539         !ctx->lpc_cof_reversed_buffer) {
01540         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01541         return AVERROR(ENOMEM);
01542     }
01543 
01544     // assign quantized parcor coefficient buffers
01545     for (c = 0; c < num_buffers; c++) {
01546         ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;
01547         ctx->lpc_cof[c]   = ctx->lpc_cof_buffer   + c * sconf->max_order;
01548     }
01549 
01550     // allocate and assign lag and gain data buffer for ltp mode
01551     ctx->use_ltp         = av_mallocz(sizeof(*ctx->use_ltp)  * num_buffers);
01552     ctx->ltp_lag         = av_malloc (sizeof(*ctx->ltp_lag)  * num_buffers);
01553     ctx->ltp_gain        = av_malloc (sizeof(*ctx->ltp_gain) * num_buffers);
01554     ctx->ltp_gain_buffer = av_malloc (sizeof(*ctx->ltp_gain_buffer) *
01555                                       num_buffers * 5);
01556 
01557     if (!ctx->use_ltp  || !ctx->ltp_lag ||
01558         !ctx->ltp_gain || !ctx->ltp_gain_buffer) {
01559         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01560         decode_end(avctx);
01561         return AVERROR(ENOMEM);
01562     }
01563 
01564     for (c = 0; c < num_buffers; c++)
01565         ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;
01566 
01567     // allocate and assign channel data buffer for mcc mode
01568     if (sconf->mc_coding) {
01569         ctx->chan_data_buffer  = av_malloc(sizeof(*ctx->chan_data_buffer) *
01570                                            num_buffers * num_buffers);
01571         ctx->chan_data         = av_malloc(sizeof(*ctx->chan_data) *
01572                                            num_buffers);
01573         ctx->reverted_channels = av_malloc(sizeof(*ctx->reverted_channels) *
01574                                            num_buffers);
01575 
01576         if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {
01577             av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01578             decode_end(avctx);
01579             return AVERROR(ENOMEM);
01580         }
01581 
01582         for (c = 0; c < num_buffers; c++)
01583             ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;
01584     } else {
01585         ctx->chan_data         = NULL;
01586         ctx->chan_data_buffer  = NULL;
01587         ctx->reverted_channels = NULL;
01588     }
01589 
01590     avctx->frame_size = sconf->frame_length;
01591     channel_size      = sconf->frame_length + sconf->max_order;
01592 
01593     ctx->prev_raw_samples = av_malloc (sizeof(*ctx->prev_raw_samples) * sconf->max_order);
01594     ctx->raw_buffer       = av_mallocz(sizeof(*ctx->     raw_buffer)  * avctx->channels * channel_size);
01595     ctx->raw_samples      = av_malloc (sizeof(*ctx->     raw_samples) * avctx->channels);
01596 
01597     // allocate previous raw sample buffer
01598     if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {
01599         av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
01600         decode_end(avctx);
01601         return AVERROR(ENOMEM);
01602     }
01603 
01604     // assign raw samples buffers
01605     ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;
01606     for (c = 1; c < avctx->channels; c++)
01607         ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;
01608 
01609     return 0;
01610 }
01611 
01612 
01615 static av_cold void flush(AVCodecContext *avctx)
01616 {
01617     ALSDecContext *ctx = avctx->priv_data;
01618 
01619     ctx->frame_id = 0;
01620 }
01621 
01622 
01623 AVCodec als_decoder = {
01624     "als",
01625     AVMEDIA_TYPE_AUDIO,
01626     CODEC_ID_MP4ALS,
01627     sizeof(ALSDecContext),
01628     decode_init,
01629     NULL,
01630     decode_end,
01631     decode_frame,
01632     .flush = flush,
01633     .capabilities = CODEC_CAP_SUBFRAMES,
01634     .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
01635 };
01636